CVE-2026-74569

A flaw was found in the Linux kernel's netfilter Session Initiation Protocol (SIP) connection tracking module (nf_conntrack_sip). A remote attacker could send specially crafted SIP messages that cause an integer overflow during Network Address Translation (NAT) rewrite delta calculations. This overflow leads to a use-after-free vulnerability, which can result in memory corruption and potentially a denial of service or arbitrary code execution.

This vulnerability is rated as Important severity because successfully exploiting this memory corruption flaw can destabilize the operating system kernel or trigger a denial of service on systems functioning as network gateways. Exploitation requires the host to process SIP network streams with active NAT connection tracking helpers enabled. In default Red Hat Enterprise Linux configurations, automatic helper assignment is disabled, which significantly restricts exposure unless administrators have explicitly configured firewall rules to inspect and translate SIP traffic.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.